As wireless and other networks become increasingly available and increasingly able to provide advanced levels of service, digital communications are becoming more and more commonplace. Indeed, portable communications devices such as telephones, personal digital assistants, portable computers and the like are widely carried and relied upon by consumers for continuous communications. Similarly, the demand for wireless and other communications services continues to be significant in industrial, governmental, homeland defense, military and other settings. In military and homeland defense settings, in particular, it can be very important that certain communications be quickly and accurately received in an efficient manner.
Computer networks generally operate using a variety of protocol “languages” that allow different nodes to communicate with each other. Many of these protocols are widely deployed on the public Internet and elsewhere, and are therefore referred to as “internet protocols”. In particular, the TCP/IP family of protocols has been widely deployed in public, private and governmental settings. These protocols, while widely used, can have a number of inherent drawbacks in certain settings and applications. The packet-switched nature of certain internet protocols, for example, is generally considered to be relatively inefficient for use in routing certain types of traffic, including voice traffic. This is because every conventional TCP/IP packet used to transport the underlying data contains routing and other “header” information that consumes bandwidth on the transport link. While this header information typically allows for effective routing (as well as improved security and/or other features), the extra data added to the data stream potentially reduces the amount of traffic that can be transmitted on a particular communications link. Wireless communications links, for example, are particularly limited in bandwidth, so the extra bandwidth consumption used to transmit conventional TCP/IP and other packet-switched protocol headers is disadvantageous.
A number of attempts have been made to reduce the adverse effects of packet-switched headers, with varying levels of success. The robust header compression (ROHC) protocols set forth in Internet RFCs 3095 and 3242, for example, describe several techniques for compressing packet switched data through the use of in-band signaling. This signaling, however, is less useful over links that experience significant time delays, such as satellite links. Moreover, the in-band signaling consumes over-the-air bandwidth, thereby reducing the overall effectiveness of such techniques.
As a result, it is desirable to create systems and techniques for efficiently delivering packet-switched data. Other desirable features and characteristics will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.